William baxtee



W. BAXTER. Steam-Engine Reversing-Gear.

No. 223,632. Patented Jgn..20,1880.

I film/Jan NVPETEHS. FHOTO LfTMOGRAPHER, WASHINGTONv D1 6.

UNITED STATES PATENT OFFICE.

WILLIAM BAXTEB, OF NEWARK, NEW JERSEY.

STEAM-ENGINE REVERSlNG-GEAR.

SPECIFICATION forming" part of Letters Patent No. 223,632,dated January 20, 1880.

Application filed May 28, 1879.

To all whom it may concern Be it known that I, WILLIAM BAXTER, of the city of Newark, in the county of Essex and State of New Jersey, have invented a new and useful Improvement in Steam-Engine Re versing-Gears, which improvement is fully described in the following specification.

My invention relates to an improvement in steam-engine reversinggears and cut-offs for reciprocating engines and it consists in a novel mode of securing a shifting eccentric upon the crank-shaft of the engine, and in a peculiar device for shifting the eccentric while the engine is in motion, to reverse the motion of the engine or alter the point of cutting oil, and in setting the center of the eccentric in a special relation to the shaft and the enginecrank.

Figure 1 of the drawings is a side view of a crank-shaft provided with my improved eccentric. Fig. 2 is a plan of the shaft with the traveler and clutch-ring. Fig. 3 is an end view of the crank-shaft, showing the traveler fitted thereon and the eccentric in its central position. Fig. 4 is a similar view, showing the eccentric at one extreme position; and Fi g. 5 is a detached view of collar 0.

The eccentric a is mounted upon the shaft between two collars or flanges, b c, the collar I) being secured to the shaft and provided on the side toward the eccentric with V-shaped ribs f, which fit into corresponding grooves g in the side of the eccentric, while the collar 0 is held firmly beside the eccentric by a clamp screw or screws tapped through the collar and pressed against the crankshaft e.

Other set-screws, d, with tapering points i, are fitted into the collar 0, and are applied to tapering holes in the shaft in such a manner as to draw the collar toward the eccentric at pleasure, to compensate for wear upon the ribs f.

The eccentric has a slot, h, formed in it, through which the shaft 0 is passed, and the slot being parallel with the ribs f, the eccentric is easily moved across the shaft between the collars b c. The crank-shaft is both enlarged and flattened where it passes through the slot h, and formed with a groove or seat, m, to receive a key of peculiar construction,

which will be hereinafter described. The slot IL is arranged at right angles to the direction of the driving-crank j, and being formed of sufficient length, the eccentric can be moved far enough from its central position to move the engine-valve its full stroke for the backward or forward motion.

To compensate for the lap always formed on plain slide-valves, the slot is not formed across the center 8 of the eccentric, but is placed across the center t of the crank-shaft e, away from the center a distance equal to the lap on one end of the valve, so that the eccentric, when in its central position, will move the valve just enough to compensate for the lap,

trie will cause the steam-ports to he opened and steam to be supplied to the piston during a part of the stroke corresponding to the extent of the eccentrics displacement from its central position.

To shift the eccentric while in motion, I employ a diagonally-grooved traveler, k, or key with inclined grooves Z formed in its top, the key being fitted to the groove m or seat in the shaft 6, and passing through suitable notches a, cut opposite the seat in the collars b and 0. One side of the slot h, opposite the seat m, is formed with inclined teeth 0, which fit the grooves l in the traveler k, and any longitudinal movement of the traveler therefore causes a transverse movement of the eccentric between the collars b and c, any transverse movement of the traveler being prevented by the sides of seat m and by its fitting the notches in collars b and c.

A clutch-ring, p, is fitted loosely to the shaft 0, and secured by a screw or pin, q, to the end of the traveler, which projects from the collars b c, and a groove, r, formed in the periphery of the ring, furnishes the means to move the traveler when the shaft 0 is in motion, as is usual with all revolving clutches.

By this construction the engine can be reversed without the use of any parts extraneous to the eccentric and the few fittings described,

while any change of position in the eccenand the operation of the engine and its valve of the eccentric can be varied affords the most convenient means of changing the cutoff point of the valve and adjusting the supply of steam exactly to the. work the engine has to perform. This is especially desirable when the speed has to be greatly varied, as in the starting, stopping, and backing of steamvessels, or when the load upon the engine is frequently changed, as in hoisting,'towing,&c.

It is evident that the operation of my grooved traveler would be the same, Whatever means are employed to afford the eccentric a transverse movement on the shaft, and as various devices, such as dovetailed and rectangular slides, are already in use for such purposes, 1 do not limit myself to the exclusive use of the ribs f and grooves g for that purpose; but

I claim the traveler and eccentric in the following manner:

1. The shifting eccentric a, provided with toothed slot h, and applied on shaft 6, between fixed collar b and adjustable collar 0, so that its centers is distant from the center t of said shaft an amount sufiioient to compensate equally for the lap of the slide-valve, whether running the engine backward or forward, in combination with the rectilinear adjustable grooved traveler 7c and the clutch-ring 19, substantially as described.

2. Eccentric a, combined with the adjustable collar 0, fixed collar 1), constructed and ap- 

